1. Field of the Invention
The present invention relates to rotating devices with magnets. More precisely, the present invention relates to a magnetically rotating upright shaft assembly that is capable of spinning for an inordinate duration of time.
2. Prior Art and Related Information
Spinning tops and gyroscopes are popular as toys and as scientific tools. There have been constant efforts to improve the duration of the spin of a top or gyroscope in order to enhance its performance for functional purposes or simply for amusement. One approach has been to apply permanent magnets in the construction of the spinning device to improve its spin duration.
In one example, the top has a conventional construction with a vertical, pointed end shaft passing through a disk. The disk has mass which gives the top its rotational inertia. In addition, the disk is a permanent magnet. The top is designed to spin on a platform, also made from a permanent magnet. The magnetic field of the disk magnet reacts with the magnetic field of the platform to somewhat stabilize the spin of the top.
Unfortunately, this system is highly unstable because it relies on a single magnet bank comprised of the spinning disk magnet and corresponding platform magnet, and the top inherently has a tendency to wander about the platform. This wandering motion causes misalignment such that what was once a delicate balance between the magnetic fields becomes unbalanced. In this unbalanced condition, the random attraction and repelling of the magnetic poles exacerbates the unbalanced spinning of the top. Eventually the top is forced off the platform or drawn into the platform. In either case, the spinning ceases quickly and abruptly.
In order to improve spin duration and because of the unstable single magnet design, the platform requires a dimple or divot to receive the pointed shaft. This diminishes the amount of wandering that the spinning top undergoes and thus maintains alignment of the magnetic fields. In practice, however, despite the presence of the dimple, the top still tends to wander off the mark causing the entire system to become unbalanced again. The problem is that if the dimple is too deep, there is significant frictional drag between it and the pointed shaft; if the dimple is not deep enough or too big, the spinning top wanders out of alignment with the magnetic field of the platform. In either case, the spin duration is shortened. There is no improvement in spin duration over that of a conventional top not using any magnets.
A similar concept is taught in U.S. Pat. No. 4,382,245 to Harrigan, which discloses a levitation device comprised of a dish-shaped magnet having an upper surface of a first polarity and a lower surface of a second polarity disposed in a coaxial relationship to a second magnet having the opposite polarity. The magnetic fields of the device position the second magnet in spaced apart relationship from the dish-shaped magnet. Accordingly, the upper magnet can be rotated to provide gyroscopic stability.
U.S. Pat. No. 5,182,533 to Ritts discloses a magnetically levitated spinning axle display apparatus. The magnetically levitated spinning axle display apparatus has a base assembly and a horizontal axle assembly. The base assembly includes a base platform having a plurality of base magnets that are disposed spaced apart along an upper surface thereof. The platform has a vertical wall forming an axle support member, which is disposed at one end. The horizontal axle assembly includes a plurality of disk-shaped magnets spaced apart therealong, and an end of the axle assembly contacts the vertical wall. The polarity configurations of the axle magnets and the base magnets are set to repel one another to create free floating levitation of the axle assembly above the base and to generate a longitudinal lateral force sufficient to keep the axle end in contact with the vertical wall.
There are other applications of a rotating shaft with permanent magnets that interact with associated magnets to suspend the rotating shaft. For example, U.S. Pat. Nos. 2,747,944 and 3,326,610 to M. Baermann disclose a bearing for instruments and machines with vertical shafts or gyrocompasses wherein the bearing for the rotary parts of instruments and machines use magnetic forces to stabilize and balance the rotating parts. Similarly, Canadian Patent No. 575,928 to M. Baermann discloses a magnetic suspension bearing for instruments and machines. Other examples of magnetic suspension systems include U.S. Pat. No. 3,493,274 to A. G. Eroslie et al.; U.S. Pat. No. 3,243,238 to J. Lyman; U.S. Pat. Nos. 2,340,122 and 2,351,424 to A. Hansen, Jr. and U.S. Pat. No. 3,614,181 to C. Meeks.
None of the foregoing, however, shows a device used to balance a rotating, upright shaft assembly through magnetic fields in order to maintain and improve spin duration of the shaft assembly upon a pivot point, wherein the shaft assembly has rotating magnets thereon and is completely unfettered by contact with any fixed structure aside from the pivot point contacting a non-dimpled surface. Indeed, the prior art devices employ a system of bearings and bushings situated on the end or ends of a rotating shaft for the purpose of maintaining alignment and location of the rotating shaft within a magnetic field. The present invention, on the other hand, employs a surrounding magnetic field to maintain the alignment and location of a rotating shaft assembly without the need for bearings, bushings, or a dimpled contact surface, all of which greatly increase friction. Hence, there is a need for a magnetically balanced spinning shaft assembly that relies on magnetic fields to significantly improve spin duration for up to 50 minutes or more.